T2FD Full coverage HF radio antenna B&W AC 3.5-30 salvage, rebuild, and testing of a classic antenna

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T2FD Full coverage HF radio antenna B&W AC 3.5-30 salvage, rebuild, and testing of a classic antenna

Рет қаралды 1,064

Күн бұрын

Video on the granddaddy of broadband HF radio antennas. In this video we take a decades old Barker and Williamson AC 3.5 - 30 terminated folded dipole antenna that was run over with a lawnmower and resurrect it. We disassemble and study the core components. We build new elements for the antenna and then we test the antenna.
#survivalcomms

Пікірлер: 22

@N2FQ 23 күн бұрын

Excellent video. I have both, the AH-710 and the B&W90. Your approach and clarity surpasses what is available from both companies and what is written on the net. Your meticulous attention to detail is superb. Kudos to you sir. Fernando N2FQ

@survivalcomms 22 күн бұрын

Thank you very much ! If I was to share something else from experience use element wire that is flexible like the flexweave that I used or even hookup wire. I had to stow a radiowavz one today that used copperweld wire and it was like rolling up a spring. Thank you for watching !

@Swamp-Fox 2 ай бұрын

Man, the build quality of the B&W certainly is impressive. I have always wondered about how they were constructed and how well they performed. Now I know. Great job on the rebuild! I think your version is better than the original!

@survivalcomms 2 ай бұрын

It was really cool getting the chance to open it up and study it. We have the modern version (BWDS 90N ) at work and it works well. Thank you very much for the compliment. My own compact version of the resistor network and transformer is in the works and I look forward to testing it out. Thanks for watching !

@baconwhiskey821 2 ай бұрын

Great video! So few cover this antenna.

@survivalcomms 2 ай бұрын

Thank you very much. You are right there isn't much coverage on it probably due to them not being handed out for internet marketing "reviews" like beads at Mardi Gras. Thanks for watching !

@rpsmith 2 ай бұрын

Excellent video. I'm personally a big dipole fan!

@survivalcomms 2 ай бұрын

Thank you and thanks for watching !

@user-ro3mn5eb9d 2 ай бұрын

Bravo my dear friend, great vid. This is the ultimate broadband NVIS antenna, higher up will do medium and long haul especially with digital modes. I have been building them 30 yrs now. I have come to make portable lightweight versions to mil spec quality. And is my go to ant for portable manpack use. also, 9:1 version might work better in the NVIS spectrum range (2-10mhz) but do not forget that unless we are speaking of a fix position and height you will always get a deviation due to the sub ground composition especially in NVIS config. where the loss is insignificant factor in the lower NVIS freq. range. antenna length and position is very forgiving in this ant. system- forest green and brown color wire is very stealthy. I have come to like the 27m version due to portability and field deployment mostly deployed in inverted vee and low hung flat top where ironically, I also get great dx with digital modes (they are king) inside of gorges and low in the valleys with high mountains! sometimes I use the ATU for 160m but its all about freq. and time of day - this monster of a antenna has been kept a secret in the military. now a days its king with digital modes and ALE, in which with its superior reception for digi modes have made this ant a resurrection masterpiece! 73 from SV1___ land !

@survivalcomms 2 ай бұрын

Thank you for sharing and thank you for watching !

@mrtechie6810 Ай бұрын

I want to build the 3 wire version (T3FD). Let's say I use a 1000 ohm termination resistor. There seems to be disagreement about the balun. Can you explain how to choose a balun ratio of 9:1 vs 12:1 vs 16:1?

@user-ro3mn5eb9d Ай бұрын

@@mrtechie6810 you should not have a great issue with the unun type (not a balun), a 16:1 is uses if you have higher Z in your system needs and operating capacity. I use this system also for portable use and my system is modular therfore I use a 9:1 unun so to utilize also on an EFRW antenna as well with a terminating resistor (beverage ant.) also and more importantly, I use this for the lower bands exclusive to NVIS communications in the field and I use the mil-spec length of The USN

@user-ro3mn5eb9d Ай бұрын

Which is 27m and it covers 2-56mhz providing a ferite core of at least 43 or higher (ft-240-43/ft 140-43 or higher than 43, around the 52....or whatever you can find it. As this is a compromise antenna system and not one is perfect try the 9:1 it should cover all your needs and surpass them. Note :for a 9:1 unun you need 10pcs. of 4.7kΩ 15w resistors in parallel which will give you the capacity of 470Ω at 150w keep in mind that the value in max pwr use is dictated by the resistor and not the unun so for ssb pep. I'd stay with 100w but for digital modes not surpass 30-50w max! Providing your antenna has a resonance below 2:1 swr. Usually it's around 1.2-1.5 swr but up to 2.1swr

@survivalcomms 29 күн бұрын

@@user-ro3mn5eb9d I have built a more compact version with a 9:1 and used some 150w microwave terminiations for the resistor network. I will be putting up a video once I get around to filming it. Thanks for sharing the info !

@zimmerking2323 2 ай бұрын

Wow - ONLY 2 'S' units. OK. Wait, what? That's 12 dB. Damn!

@survivalcomms 2 ай бұрын

Broad band and gain are like matter and antimatter never occupying the same space. Thanks for watching !

@mrtechie6810 Ай бұрын

@survivalcomms Ай бұрын

The simplest way is If the end equipment is looking for an impedance of 50 ohms your desired transformation ratio is the quotient of the resistor value divided by 50. for a 1000ohm resistor 1000 /50 = 20 or 20:1 . Thanks for watching !